Net amount of other operating income and other operating expenses arising from activities that are not part of the entity's primary revenuegenerating operations. This includes miscellaneous operating items that do not meet the definition of revenue, cost of sales, selling expenses, administrative expenses, or research and development expenses, and are presented as a separate component of operating results.

No definition available.

Name:	grfs_OtherOperatingRevenueAndExpenses
Namespace Prefix:	grfs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Segment Reporting - Additional Information (Details) € in Millions	12 Months Ended
	Dec. 31, 2025 EUR (€)	Dec. 31, 2025 location	Dec. 31, 2025 segment	Dec. 31, 2024 EUR (€)	Dec. 31, 2023 EUR (€)
Segment Reporting
Other operating revenue and expenses	€ (5,736)			€ (5,609)	€ (5,464)
Geographical information
Number of geographical segments		4	4
Intersegments
Segment Reporting
Other operating revenue and expenses					€ 7